Investigating the Role of Brönsted and Lewis Acid Sites on the Esterification of Levulinic Acid over Ti–Al–SBA-15 Bifunctional Catalysts
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Le résumé fourni par la source
In this study, titanium (Ti) and aluminum (Al) were simultaneously incorporated into the SBA-15 material using a one-step sol–gel method to obtain bifunctional acid catalysts. The physicochemical properties of the catalysts were thoroughly investigated, with particular focus on their acidity and the role of the Brönsted (BAS) and Lewis (LAS) acid sites during the esterification of levulinic acid with ethanol. Two different Si/Ti molar ratios (10 and 60) were used during the catalyst preparation, while the Si/Al molar ratio was kept constant at 10. The characterization results indicated that titanium primarily coordinates as tetrahedral Ti, yielding Lewis acid sites, with only minor amounts of TiO 2 particles or agglomerated Ti species. On the other hand, when aluminum is incorporated into SBA-15, it exhibits both tetrahedral and octahedral coordination, creating Brönsted and Lewis acid sites, resulting in a BAS/LAS ratio of 1.72. When both titanium and aluminum are incorporated simultaneously into the SBA-15 material, the catalysts display bifunctional acid properties, with BAS/LAS ratios ranging from 0.96 to 0.69. Among the catalysts evaluated, the bifunctional Ti(10)–Al(10)–SBA-15 material exhibited the highest total acid site concentration (6.6 × 10 –2 mmol/g cat ) and showed the best catalytic performance in the esterification of levulinic acid with ethanol, achieving 98% conversion at 140 °C with a turnover frequency of 6.6 × 10 –1 s –1 . The enhanced catalytic activity toward ethyl levulinate formation is associated with the presence and cooperation of both Lewis and Brönsted acid sites in the catalyst. A first-order kinetic model accurately describes the reaction kinetics over this bifunctional catalyst, resulting in an activation energy of 49 kJ/mol, consistent with previously reported values. Moreover, this catalyst demonstrated notable stability, with the conversion of levulinic acid decreasing by only 0.67% over five consecutive reaction cycles.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Investigating the Role of Brönsted and Lewis Acid Sites on the Esterification of Levulinic Acid over Ti–Al–SBA-15 Bifunctional Catalysts
- Date Crossref
- 27/05/2026
- Éditeur
- American Chemical Society (ACS)
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Universidad Michoacana de San Nicolás de Hidalgo pays non établi dans la noticeUniversité ou école supérieure
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Universidad Autónoma del Estado de México pays non établi dans la noticeUniversité ou école supérieure
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Rede de Química e Tecnologia pays non établi dans la noticeOrganisation à but non lucratif
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Office of the Secretary of Health and Human Services pays non établi dans la noticeOrganisme public
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Institut Català de Nanociència i Nanotecnologia pays non établi dans la noticeStructure de recherche
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Universidad Nacional Autónoma de México pays non établi dans la noticeUniversité ou école supérieure
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Facultad de Ingeniería Química pays non établi dans la noticeInstitution
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Facultad de Química pays non établi dans la noticeInstitution
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Secretaría de Ciencias pays non établi dans la noticeInstitution
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Centro de Nanociencias y Nanotecnología pays non établi dans la noticeInstitution
Universidad Michoacana de San Nicolás de Hidalgo, Universidad Autónoma del Estado de México et Rede de Química e Tecnologia, avec 7 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.